Do you mean where do things go when places close down?
On a few occasions, they are bought as a package, usually to open a small country centre where budgets are tight.
Generally if the machines are too far gone for repair, they are either dumped at the tip *shakes head* or pulled apart and sold as spare parts either directly to other centres or through distributors. If the machines can be serviced and put back into action then they are either bought to replace dying machines at another centre here, or sold and shipped to the National Dumping Ground (A.K.A. New Zealand).
Old wooden lanes and approaches aren't in much demand these days so they are disposed of. Synthetics can be sold to centres with wooden lanes or approaches to be installed either directly or once the wood has gone beyond a resurface. They can also be bought to upgrade older synthetics. These too are often sold and shipped offshore.
Usually someone will by most of the stuff as a package, looking for a cheaper way to upgrade an older centre. They may not buy it all tho, so you'll probably find that it goes out of the industry. Did you know Wooden Lanes & Approaches make great tables and other such furniture at Head Techs houses? Synthetic pannels are brilliant as hallway flooring or workbenches. Gearboxes, motors, distributors and tables all are great little earners if you've the time to strip/clean/rebuild and sell on ebay
Pins can be a great source of cheap firewood in winter, they burn very well and very hot.